The present invention relates generally to medical systems and methods. More particularly, the invention relates to rigid delivery systems having an inclined ultrasound array for improved imaging and curved needle for ablation treatment and methods for using such systems.
Treatment of the female reproductive tract and other conditions of dysfunctional uterine bleeding and fibroids remain unmet clinical needs. Fibroids are benign tumors of the uterine myometrial (muscle) and are the most common tumor of the female pelvis. Fibroid tumors affect up to 30% of women of childbearing age and can cause significant symptoms such as discomfort, pelvic pain, mennorhagia, pressure, anemia, compression, infertility and miscarriage. Fibroids may be located in the myometrium (intramural), adjacent to the endometrium (submucosal) or in the outer layer of the uterus (subserosal). Most commonly fibroids are a smooth muscle overgrowth that arise intramurally and can grow to be several centimeters in diameter.
Current treatments for fibroids include both pharmacological therapies and surgical interventions. Pharmacological treatment includes the administration of medications such as NSAIDS, estrogen-progesterone combinations, and GnRH analogues. All medications are relatively ineffective and are palliative rather than curative. Hysterectomy (surgical removal of the uterus) is another common treatment for fibroids. While effective, hysterectomy has many undesirable side effects such as loss of fertility, open surgery, sexual dysfunction and long recovery time. There is also significant morbidity (sepsis, hemorrhage, peritonitis, bowel and bladder injury), mortality and cost associated with hysterectomy. Surgical myomectomy, in which fibroids are removed, is an open surgical procedure requiring laparotomy and general anesthesia. Often these procedures and long with significant blood loss and can only remove a portion of the culprit tissue.
To overcome at least some of the problems associated with open surgical procedures, laparoscopic myomectomy was pioneered in the early 1990's. However, laparoscopic myomectomy remains technically challenging, requiring laparoscopic suturing which limits its performance to only the most skilled of laparoscopic gynecologists. Other minimally invasive treatments for uterine fibroids include hysteroscopy, uterine artery ablation, endometrial ablation, and myolysis.
Hysteroscopy is the process by which a thin fiber optic camera is used to image inside the uterus and an attachment may be used to destroy tissue. Hysteroscopic resection is a surgical technique that uses a variety of devices (loops, roller balls, bipolar electrodes) to ablate or resect uterine tissue. The uterus needs to be filled with fluid for better viewing and thus has potential side effects of fluid overload. Hysteroscopic ablation is limited by its visualization technique and is thus only appropriate for those fibroids that are submucosal and/or protrude into the uterine cavity.
Uterine artery embolization was introduced in the early 1990's and is performed through a groin incision by injecting small particles into the uterine artery to selectively block the blood supply to fibroids. Complications include pelvic infection, premature menopause and severe pelvic pain. In addition, long term MRI data suggest that incomplete fibroid infarction may result in regrowth of infarcted fibroid tissue and symptomatic recurrence.
Endometrial ablation is primarily a procedure for dysfunctional (or abnormal) uterine bleeding and may be used at times for fibroids. Endometrial ablation relies on various energy sources such as cryo energy, microwave energy and radiofrequency energy. Endometrial ablation destroys the endometrial tissue lining the uterus but does not specifically treat fibroids. This technique is also not for women who desire future childbearing. Endometrial ablation remains an excellent therapy for dysfunctional uterine bleeding but is limited in its ability to treat fibroids.
Myolysis was first performed in the 1980's using lasers or RF energy to coagulate tissue, denature proteins and necrose myometrium with laparoscopic visualization. Laparoscopic myolysis can be an alternative to myomectomy, as the fibroids are coagulated and then undergo coagulative necrosis resulting in a dramatic decrease in size. As with all laparoscopic techniques, myolysis treatment is limited by the fact that it can only allow for visualization of subserosal fibroids.
Needle myolysis uses a laparoscope or open technique to introduce one or more needles into a fibroid tumor under direct visual control. Bipolar or unipolar radio frequency (“RF”) current, cryo energy, or microwave energy is then delivered between two adjacent needles, or unipolar current between a single needle and a distant dispersive electrode affixed to the thigh or back. The aim of needle myolysis is to coagulate a significant volume of the tumor and thereby cause it to shrink substantially. The traditional technique is to make multiple passes through different areas of the tumor using the coagulating needle to destroy many cylindrical cores of abnormal tissue. However, the desirability of multiple passes is mitigated by the risk of adhesion formation, which is thought to increase with increasing amounts of injured uterine serosa, and by the operative time and skill required. Myolysis can be an alternative to myomectomy, as the fibroids are coagulated and then undergo coagulative necrosis resulting in a dramatic decrease in size. Myolysis is generally limited by the fact that it is used with direct visualization and can therefore only see (and therefore treat) subserosal fibroids.
To overcome the limitations of current techniques, it would be desirable to provide a minimally invasive approach to selectively eradicate fibroid tumors within the uterus. A solution in the treatment of fibroid tumors that combines imaging and ablation in one simple hand held system is needed. It would be further desirable if the system and method could locate and treat all types of fibroids in the uterus in a safe and effective manner with minimum risk and discomfort for the patient. It would be still further desirable if the systems could employ multiple interchangeable components both to permit selective sterilization or re-use of the components and to permit the system to be configured individually for patients having different anatomies and needs. It would be still further desirable if such systems could provide for improved imaging (e.g., enhanced field of view) and variability in the curved needle for ablation treatment. At least some of the objections will be met by the inventions described below.